The present invention relates to a radio module having a radio device, an internal microprocessor device connected to the radio device and an interface which is connected to the microprocessor device and has connection pins for connecting the radio module to at least one external electrical apparatus. The radio module is designed such that it has at least two modes of operation in which it can be operated; specifically, a passive mode of operation, in which an external microprocessor device is connected to the radio module as an external electrical apparatus, the radio module is used as a modem for the external microprocessor device, and the radio module can be actuated by the external microprocessor device using modem actuation signals, preferably AT commands, and at least one active mode of operation, in which at least one actuator or sensor is connected to the radio module as an external electrical apparatus, the radio module actuates and/or reads the at least one actuator or sensor and, for its part, can be actuated externally via the radio device.
A radio module of this type is sold by the company Wavecom under the product name WismoPac. This previously known radio module can be operated in two modes of operation; specifically, in a first mode of operation, in which the radio module operates as a modem, and in a second mode of operation, in which the modem is used in a telecommunication terminal, such as a mobile phone, and undertakes all control functions therein. The previously known radio module has an interface with 222 connection pins, among which a first group of connection pins forms a serial interface, namely an RS-232 interface, for modem operation using AT commands. All other connection pins form a second group of connection pins which are responsible for all other tasks of the previously known module; for example, for the connection of microphones, loudspeakers, SIM cards or other components.
The present invention is directed toward specifying a radio module which requires as few connection pins as possible.